This invention relates to plumbing connections and fittings, and is more particularly concerned with devices for temporary connection of recreational vehicles to water supplies for use within the vehicle for cooking, washing, or drinking.
Many persons use recreational vehicles as a means of travel, and as a place of lodging when traveling. Such recreational vehicles may include so-called RVs, campers, travel trailers, or may be houseboats, sailboats or yachts. At each location or campsite, where the vehicle may be parked for overnight stay or longer, there is usually a fresh water hook-up, including a tap or spigot for supplying water to the vehicle. The user can connect a flexible hose, which is similar to a common garden hose, between the hook-up and a water supply inlet pipe on the vehicle, and then can turn on the water by opening a valve at the hook-up. When the time comes to depart the campsite, the user shuts off the hook-up valve and then disconnects the hose from the hook-up tap and the inlet pipe. At this time, the back pressure in the vehicle""water system remains until it is somehow relieved. If the user simply unscrews the fittings, this can result in the water spraying the user. The usual procedure to avoid this is to go into the RV or camper, open a water valve, e.g., in the sink or shower, to relieve the back pressure, and then go back outside to disconnect the hose.
A prior attempt to deal with the spraying problem when the hose is disconnected is discussed in Sproule U.S. Pat. No. 5,390,691. In that patent a special water valve is placed on the vehicle water inlet, with the water valve having a separate coupling for the supply hose. The device proposed in that patent has intersecting bores for the hose connection, the vehicle inlet connection and the water tap, so that there is a 90-degree bend in the main water flow path. Also, as the valve incorporated into the device is of standard design intended to regular use as an outdoor water tap, regular maintenance is needed, such as annual replacement of the valve washer. If this is neglected, valve failure can lead to loss of water pressure in the RV or camper. Also, where the pressure relief valve is located at the vehicle inlet end of the hose, rather than at the hook-up end, it may require first shutting off the hook-up, then walking over to the RV to bleed the hose, and then walking back to the hook-up to disconnect the hose from it.
Accordingly, it is an object of the present invention to provide a pressure relief device that avoids the drawbacks of the prior art.
It is another object to provide a pressure relief device of straightforward, simple design, with a minimum of bends, and which is reliable and simple to use.
It is a further object to provide a pressure relief device that connects to one end or the other of the water supply hose between the hook-up and the supply inlet.
It is yet another object to minimize the risk of water spraying out onto the person disconnecting the water supply hose from the water hook-up.
In accordance with one aspect of the present invention, a pressure relief device is provided for use with water supply connection for a mobile camping vehicle. A flexible water hose is connected at one end by a threaded fitting to a water hook-up and at another end to an water supply inlet of the vehicle. The a pressure relief device is placed in line with the hose for relieving back pressure when the user disconnects the hose from the water hook-up. The device includes a tubular nipple having threaded fittings on its ends to mate with corresponding fittings on the hose at one end and on one or both of said hook-up and said inlet at the other end. Preferably, these are the same diameter and thread, and can be one male and one female. A needle-valve pressure relief is affixed onto the nipple about midway between the fittings. There is an opening for fluid communication with the interior of the tubular nipple. The needle-valve pressure relief has a needle-valve seat assembly affixed onto the tubular nipple, and a needle valve with screw threads that mate with threads in the needle-valve seat The needle valve can be manually rotated into or out of closure with the seat. The needle-valve said seat structure has a pressure-relief bleed hole to direct any escaping water to one side of the needle-valve seat. This bleed hole is oriented to direct any blast of water to one side of the nipple. The nipple can also be distinctively colored on opposite sides, e.g., red on one side and white on the other, so that the user can know at a glance the direction that any water spray is likely to go.
This device can be favorably attached at the hook-up end of the hose, so that the user can bleed the back pressure from the hose, after turning off the hook-up valve, without having to move to the RV water inlet.
In a preferred embodiment, the pressure relief nipple may be brass and the valve seat may be brazed or welded onto it. The needle valve stem may have a key-type handle that is removably mounted on the end, so that the key can be removed to discourage tampering. The needle valve usually requires no maintenance and has no parts expected to exhibit wear.
The above and many other objects, features, and advantages of this invention will be more fully appreciated from the ensuing description of a preferred embodiment, which is to be read in conjunction with the accompanying Drawing.